COLLEGE STATION, Texas — The words "youth" and "inexperience" are frequently used to describe the Texas A&M defense this season.

The struggles are significant. The Aggies rank near the bottom of the FBS in most defensive statistical categories. According to ESPN Stats & Information, the five teams that have allowed more yards per game than the Aggies -- New Mexico State, Idaho, California, Nevada and Indiana -- have a combined record of 8-27.

Texas A&M is fortunate enough to have a 5-2 record (2-2 in the SEC). It certainly helps to have one of the nation's most high-powered offenses and a reigning Heisman Trophy winner at quarterback (Johnny Manziel).

For defensive coordinator Mark Snyder and his staff, it has been a challenge from the start of the season. Suspensions, injuries and ineffectiveness are all to blame.

The Aggies currently have 11 freshmen in their defensive two-deep depth chart. Two true freshmen (defensive tackle Isaiah Golden and linebacker Darian Claiborne) are starting. The four defensive line first-team spots include Golden and two sophomores. At linebacker, a former receiver who moved to linebacker this offseason (Nate Askew) is the starter at strongside linebacker. Of the seven linebackers on the Aggies' two-deep, only one (Steven Jenkins) started a full season at the position before this year.

Head coach Kevin Sumlin's first signing class that was completely under his watch had 32 members, 18 of whom were on defense. Of those 18, a dozen have already played this season.

But how did the Aggies get to this point, playing this many freshmen and newcomers? There are some juniors and seniors on the field, but there aren't nearly as many as there were a year ago when the Aggies went 11-2 in their debut season in the SEC.

In 2012, the Aggies were fortunate to have the benefit of some good leaders on defense and others who were productive. At linebacker, Sean Porter and Jonathan Stewart both provided leadership and production. Along the defensive line, Spencer Nealy made the move from defensive end to defensive tackle effectively despite not having the ideal size for the position. Steven Terrell was a steady and heady player at free safety. All four of those players were seniors and part of the 2009 recruiting class. So was Dustin Harris, who didn't always start but played plenty at cornerback and was the team's primary punt returner.

One defensive player still remains from that 2009 class: defensive tackle Kirby Ennis, who started last season and this year but suffered a season-ending knee injury on Sept. 28 against Arkansas. But last year's A&M starting defense was more than half made up of what turned out to be a solid recruiting class on the defensive side of the ball.

So to understand why A&M is in the position it is now, take a look at the recruiting classes on defense since then:

In 2010, the Aggies signed seven defensive players and two more that were offensive players but eventually moved to defense. Defensive end Damontre Moore turned out to be a star, but declared for early entry into the 2013 NFL draft with a year of eligibility remaining. For a team that's lacking in its pass rush (only three FBS teams have fewer sacks than Texas A&M's seven this season) a guy like that could help. Of the remainders in that class, three are starting: Toney Hurd Jr. at nickel back, Gavin Stansbury at defensive end and Askew, who was recruited and spent his first three years at receiver, at strongside linebacker. Two others (defensive tackle Ivan Robinson and quarterback Clay Honeycutt, who's now a reserve safety) are playing but not starting. Nehemiah Hicks was considered to be either a defensive end or tight end and became a tight end. The other two players in the defensive class are no longer on the team.

The 2011 class -- the final class signed by former head coach Mike Sherman -- brought 13 defensive players. Deshazor Everett, a cornerback with ability to play safety, is currently the defense's best player. Safeties Howard Matthews and Floyd Raven and linebacker Steven Jenkins also emerged as starters out of that group. One of the big fish landed late in that class, defensive end Brandon Alexander, has rarely played. He's now getting some playing time at tight end. Linebacker Donnie Baggs entered this season as the starting middle linebacker but is now a reserve. Tyrell Taylor is rotating at defensive end. The rest of the group hasn't made any impact at all. Five players in that group are no longer with the program.

The 2012 class, the first one Sumlin signed after essentially two months on the job, had some holdovers that committed to the program under Sherman. It is a mixed bag. Four of those players are starting as either true sophomores (Julien Obioha at defensive end, Alonzo Williams at defensive tackle and De'Vante Harris at cornerback) or in one case, a senior (cornerback Tramain Jacobs, who was a junior college transfer). Defensive end Tyrone Taylor, brother of Tyrell, gets some playing time at defensive end. Edward Pope, who was a receiver/defensive back, is playing receiver for the Aggies. A car accident took away one member from that class -- defensive tackle Polo Manukainiu, who died in a crash in July and is being honored by the team every week this season. A spinal injury took away another member, linebacker Michael Richardson, who played as a freshman. He had successful surgery and was fortunate to not suffer any major physical issues, but is no longer playing football. Defensive back Kenneth Marshall, though on the team, was not part of the 105-man roster during preseason training camp. Linebacker Jordan Richmond transferred to Navarro College in the offseason and one player in the class, defensive tackle Edmund Ray, never made it to campus because of qualifying issues.